Dual effects of leptin in perioperative gas exchange of morbidly obese patients.

Leptin has shown positive effects on respiratory function in experimental settings. The role of leptin on perioperative respiratory function in morbidly obese patients has not been established. We performed a retrospective analysis of morbidly obese patients undergoing laparoscopic sleeve gastrectomy. Fasting serum leptin and interleukin (IL)-6 were measured preoperatively, and arterial blood gases were obtained pre- and postoperatively. Outcome variables were arterial partial pressure of oxygen (PaO2), arterial partial pressure of carbon dioxide (PaCO2), and differences in PaO2 and PaCO2 between pre- and postoperative values (ΔPaO2, ΔPaCO2; postoperative minus preoperative). Patients with lower (<40 µg/L) and higher (≥40 µg/L) leptin levels were compared. Bravais-Pearson's correlation, multiple linear regression, and logistic regression analysis were performed. A total of 112 morbidly obese patients were included. Serum leptin was significantly higher in females than in males (42.86±12.89 vs. 30.67±13.39 µg/L, p<0.0001). Leptin was positively correlated with body mass index (r = 0.238; p = 0.011), IL-6 (r = 0.473; p<0.0001), and ΔPaO2 (r = 0.312; p = 0.0008). Leptin was negatively correlated with preoperative PaO2 (r = -0.199; p = 0.035). Preoperative PaO2 was lower, ΔPaCO2 was smaller, and ΔPaO2 was greater in the high leptin group than in the low leptin group. In multiple regression analysis, leptin was negatively associated with preoperative PaO2 (estimate coefficient = -0.147; p = 0.023). In logistic regression analysis, leptin was associated with improved ΔPaO2 (odds ratio [OR] = 1.104; p = 0.0138) and ΔPaCO2 (OR = 0.968; p = 0.0334). Leptin appears to have dual effects related to perioperative gas exchange in obese patients undergoing bariatric surgery. It is associated with worse preoperative oxygenation but improved respiratory function after surgery.

Profile of sugammadex for reversal of neuromuscular blockade in the elderly: current perspectives.

The number of elderly patients is increasing worldwide. This will have a significant impact on the practice of anesthesia in future decades. Anesthesiologists must provide care for an increasing number of elderly patients, who have an elevated risk of perioperative morbidity and mortality. Complications related to postoperative residual neuromuscular blockade, such as muscle weakness, airway obstruction, hypoxemia, atelectasis, pneumonia, and acute respiratory failure, are more frequent in older than in younger patients. Therefore, neuromuscular blockade in the elderly should be carefully monitored and completely reversed before awakening patients at the end of anesthesia. Acetylcholinesterase inhibitors are traditionally used for reversal of neuromuscular blockade. Although the risk of residual neuromuscular blockade is reduced by reversal with neostigmine, it continues to complicate the postoperative course. Sugammadex represents an innovative approach to reversal of neuromuscular blockade induced by aminosteroid neuromuscular-blocking agents, particularly rocuronium, with useful applications in clinical practice. However, aging is associated with certain changes in the pharmacokinetics of sugammadex, and to date there has been no thorough evaluation of the use of sugammadex in elderly patients. The aim of this review was to perform an analysis of the use of sugammadex in older adults based on the current literature. Major issues surrounding the physiologic and pharmacologic effects of aging in elderly patients and how these may impact the routine use of sugammadex in elderly patients are discussed.

Obesity and perioperative noninvasive ventilation in bariatric surgery.

The incidence and prevalence of obesity continues to increase globally. Physicians will therefore provide care for an increasing number of obese patients in their clinical practice. Optimal management of these patients is required to minimize the risk of perioperative complications that increase morbidity and mortality. Obesity affects the respiratory function. It is generally associated with reduced lung volume with increased atelectasis, decreased lung and chest wall compliance, increased airway resistance, and moderate to severe hypoxemia. These physiologic alterations are generally more pronounced in obesity complicated by obstructive sleep apnea syndrome or obesity hypoventilation syndrome. Anesthesia and surgery can profoundly impair respiratory function, increasing the risk of postoperative respiratory complications and acute respiratory failure. Certain comorbidities associated with obesity (e.g., metabolic syndrome, obstructive sleep apnea, pulmonary disease) further increase the risk of perioperative complications. Non-invasive ventilation (NIV) is emerging as an important strategy to minimize perioperative complications. It may ameliorate obesity-related comorbidities, counteract upper airway obstruction, reduce hypoventilation and atelectasis, improve gas exchange and respiratory function, relieve dyspnea, and decrease breathing effort in obese patients in the perioperative period. Thus, NIV may lower the risk of acute respiratory failure after bariatric surgery. Selecting the appropriate interface and type of NIV is fundamental for increasing the likelihood of NIV success in such high-risk patients. NIV is a safe therapy, which should be considered in the perioperative period to help optimize the management of obese patients undergoing bariatric surgery and improve their postoperative course.